ITU G.992.3 is an ITU (
International Telecommunication Union) standard, also referred to as
ADSL2 or
G.dmt.bis. It optionally extends the capability of basic
ADSL in data rates to 12
Mbit/s downstream and, depending on Annex version, up to 3.5 Mbit/s upstream (with a mandatory capability of ADSL2 transceivers of 8 Mbit/s downstream and 800 kbit/s upstream). ADSL2 uses the same bandwidth as ADSL but achieves higher throughput via improved modulation techniques. Actual speeds may reduce depending on line quality; usually the most significant factor in line quality is the distance from the
DSLAM to the customer's equipment.